Support body for a blank

ABSTRACT

The invention relates to a support body for a blank, whereby the support body possesses a receiving opening for the blank that is surrounded by an inner circumferential surface, which terminates in an upper and a lower edge, and whereby a blank fixed in position within the support body is bonded to the latter by means of an adhesive agent. In order to be able to easily introduce the adhesive agent into a gap between the blank and the support body it is intended that the inner circumferential surface possesses at least one depression and/or elevation extending to accommodate the adhesive agent.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.15/000,385, filed on Jan. 19, 2016, which claims the benefit of andpriority to German Application Ser. No. 102015100666.9, filed on Jan.19, 2015, which are herein incorporated by reference for all purposes.

FIELD OF THE INVENTION

The invention relates to a support body for a blank, in particular ablank consisting of ceramic, such as zirconium oxide or a glass ceramic,whereby the support body possesses a receiving opening for the blankwith an inner circumferential surface that terminates in an upper and alower edge, and und whereby when the blank is fixed in the support body,the blank is bonded to the support body by means of a binding agent. Inparticular, the support body is embodied with a hollow-cylindergeometry. The support body circumferentially surrounds the blank, whichin particular possesses a disk shape or cylinder shape.

BACKGROUND OF THE INVENTION

WO 02/45614 A1 discloses a mounting device for a ceramic blank thatcomprises a rectangular holder, which in turn accepts a rectangularframe, in which a blank is fixed in position by means of gluing. Atwo-component adhesive, for example, is introduced into an adhesive gapthat exists between the blank and the frame.

In accordance with EP 0 982 009 A2, a blank is inserted into a passageopening of a plate-shaped support body.

A holding arrangement for workpieces according to WO 2007/143765comprises a frame, in which a holder arrangement, which can accommodatea work piece by friction lock, is fixed in position by clamping.

A blank mount for a dental milling machine in accordance with DE 20 2013103 515 U1 comprises a ring-shaped work-piece holder with clampingholders that are used to fix the blank in position.

In accordance with DE 20 2010 001 125 U1, detachable fastening elementsare used to mount a blank in a mounting fixture.

For mounting a blank in a holder in accordance with DE 20 2012 008 015U1, fastening means are provided that reach over and/or under the blank.

In accordance with DE 10 2007 013 675 A1, a UV curing adhesive is usedto mount a blank in a support body, which at least partially consists ofa material that is transparent at least in the UV region of thespectrum.

In accordance with DE 10 2012 201 744 A1, a molded body is fixed inposition in a workpiece holder by means of fasteners, whereupon themolded body is machined in a dental milling machine.

Known from DE 10 2005 008 004 A1 is a processing method for a workpiecethat is fixed in position within a tenter by means of cast resin.

During the manufacture of a dental prosthesis, in accordance with WO95/30382 A1, a blank is embedded in a ring, which is clamped in thechuck of a processing machine.

A silicon block to be worked is connected firmly to a support. To allowthe support to be reliably bonded to the silicon block, the support isprovided with a profile pattern (DE 10 2009 023 122 A1).

Holders of this type are required to be able to clamp a blank in aprocessing machine with great positional accuracy. In this, it must notonly be ensured that the holder retains its shape during clamping butalso that the blank with respect to the support body assumes a uniqueposition that cannot change during the processing.

The objective of the present invention is to further develop a supportbody of the above-mentioned type, in particular for accepting a blankconsisting of ceramic, such as zirconium oxide, which is to be processedin a milling machine, for example, in such a way that with simpleconstructive measures, a secure positional fix will become possibleusing an adhesive agent, which can be introduced easily in between thesupport body and the blank and can remain between the support body andthe blank to the required extent until curing has taken place.

SUMMARY OF THE INVENTION

It is an object of the present invention to at least partially overcomethis problem, and to provide a medical device, such as an implant,having a surface, which reduces the risk for infection upon contact ofthe medical device with living tissue.

According to one aspect, the present invention is directed to a supportbody for a blank, in particular a blank consisting of ceramic such aszirconium oxide or a glass ceramic, whereby the support body comprises areceiving opening for the blank that is surrounded by an innercircumferential surface bordered by an upper and a lower edge and whenthe blank is fixed in position within the support body, it is bonded tothe latter by means of an adhesive agent, whereby the support body inparticular possesses a hollow cylindrical geometry and circumferentiallysurrounds the blank, which in turn preferably possesses a disk-shaped orcylindrical geometry, wherein the inner circumferential surfacepossesses a structure in form of at least one depression that extends toat least one edge and/or at least one elevation to accommodate theadhesive agent.

In another aspect, any of the aspects of the present invention may befurther characterized by one or any combination of the followingfeatures: wherein the structure is formed by at least one, in particularby several preferably pocket-shaped depressions within the wall of thesupport body that is bordered by the inner circumferential surface,whereby the depressions extend to the at least one edge; wherein fromthe receiving-side area of both the upper and the lower edge originatedepressions, which preferably terminate at some distance from the centerof the inner circumferential surface—relative to the latter's height;wherein the depression is bordered by a first surface extending alongthe interior circumferential surface and lateral surfaces extendingperpendicularly thereto, and in that the distance from the first surfaceto the central axis of the support body decreases from one edge alongthe direction towards the opposite edge; wherein the depressions areuniformly distributed along the inner circumference of the support body;wherein the depressions originating from one edge will exhibit the samedistances to a reference mark of the support body as the depressionsoriginating from the other edge after a rotation of the support body by180° about its transverse axis; wherein the structure is formed in asupplementary or alternative manner by at least one elevation such asridge and/or depression that extends at some distance to the edge andoriginates from the inner circumferential surface of the wall, wherebypreferably the elevation and/or depression extending at some distance tothe edge is provided in addition to the at least one preferablypocket-shaped depression; wherein from the inner circumferential surfaceoriginate one or several projections, such as ridges that at least insections extend above the height of the inner circumferential surfaceand serve as support for the blank; wherein the first surface of thedepression encloses with the inner circumferential surface an angle α20°≤α30°, in particular α=25°; wherein in the central area of the innercircumferential surface extends a preferably circumferential ridge ordepression, such as a groove, which in particular extends in parallel tothe edges; wherein in the area of the depression, the wall of thesupport body in the edge area possesses a thickness D1 and outside ofthe depressions it possesses a thickness D2, whereby 8*D1≥D2≥2*D1;wherein the distance A1 between successive depressions relative to thelength A2 of the respective depression along the circumferentialdirection obeys A2≤A1≤2*A2; wherein the support body consists ofplastic, in particular of fiber reinforced plastic such as glass fiberreinforced plastic such as thermoplastic, whereby in particular thethermal expansion coefficient WAK_(H) of the material is matched to thethermal expansion coefficient WAK_(R) of the blank, and in particularthe thermal expansion coefficients differ no more than 20%, preferablyno more than 10%; wherein the fiber content such as glass fiber contentof the support body amounts to between 30% by volume and 70% by volume,in particular approximately 50% by volume; or any combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective representation of a support body;

FIG. 2 shows a top view onto the support body of FIG. 1;

FIG. 3A shows a sectional view along the line B-B of FIG. 2;

FIG. 3B shows a cross-sectional view along the line C-C of FIG. 3A;

FIG. 4 shows the support body of FIGS. 1 to 3A together with a blank;

FIG. 5 shows a detail “A” of FIG. 3A;

FIG. 6 shows a detail “B” of FIG. 2;

FIG. 7 shows a perspective representation of a support body according toanother aspect of the present invention;

FIG. 8 shows a perspective representation of a support body shown inFIG. 7 together with a blank;

FIG. 9 shows a perspective representation of a support body togetherwith a blank shown in FIG. 8 at the start of a machining process;

FIG. 10 shows a perspective representation of a support body togetherwith a blank shown in FIG. 8 at the end of a machining process.

DETAILED DESCRIPTION OF THE INVENTION

In the present invention, this objective is substantially met that theinner circumferential surface possesses a structure that is formed by atleast one depression that extends to at least one edge of the innercircumferential surface and/or at least one elevation that protrudesfrom the inner circumferential surface for the acceptance of an adhesiveagent.

In accordance with the invention, the structural pattern of the innersurface, i.e. the formation of at least one depression and/or oneelevation, makes it possible to introduce an adhesive agent into thespace between the blank and the support body to the required extent,which remains in the gap sufficiently long for curing to take place.

In particular, it is intended that the structure is formed by at leastone, in particular by several preferably bag-shaped depressions in thewall of the support body that is bordered by the inner circumferentialsurface, which extends or extend to the at least one edge, i.e.originates or originate from the edge.

This to be emphasized embodiment of the structure ensuresthat—independently of a small distance between the blank and the innercircumferential surface of the support body-adhesive agent can beintroduced to an adequate degree, in particular via the pocket-shapeddepression or depressions. The depressions are arranged at some distancefrom each other so that the wall thickness of the support body, whichpreferably possesses a ring-shaped or hollow-cylindrical geometry,remains constant over large areas, which ensures the required amount ofstability to ensure that the support body does not deform during theclamping process.

In particular it is intended that depressions originate in thereceiving-side areas of both the upper and the lower edge and preferablyend at some respective distance to the center—with respect to itsheight—of the inner circumferential surface.

In a top view onto the support body, the depressions originating fromthe lower or upper edge are arranged offset with respect to each other,so that there is no weakening of the wall of the support body betweenthe inner boundary of a depression and the opposite edge.

In order to be able to introduce the adhesive agent easily and at thesame time to weaken the wall as little as possible, a furtherdevelopment intends that the depression is bordered by a first surfacethat extends along the inner circumferential surface and a lateralsurface extending perpendicular thereto, and that the distance of thefirst surface to the central axis of the support body decreases from itsorigin at one edge along the direction towards the opposite edge.

The first surface, which extends along the circumferential surface andalso extends into the latter consequently possesses a ramp shape andconsequently extends inclined with respect to the longitudinal axis ofthe support body. The first surface is bordered by lateral surfaces,which do not necessarily have to extend in parallel, but in a sectionalview can exhibit a trapezoidal geometry together with the first surface.Thus the edges of the first surface may have the shape of a trapeze.

In order to offer enough free space to introduce the adhesive agent,even if there is only a narrow gap between the blank and the innercircumferential surface, it is intended that in the area of thedepressions, the wall of the support body in the edge area has athickness D1 and that the wall outside of the depressions has a wallthickness D2, with 8*D1≥D2≥2*D1. D2 may for example be 1.5 mm to 5 mm,in particular D2=2.5 mm.

In a preferred manner the invention intends that the distance A1 betweensuccessive depressions relative to the length A2 of the respectivedepression in the circumferential direction obeys A2≤A1≤2*A2. Thedistances A1 and A2 may be specified as arc length if the support bodypossesses a circular geometry. In this case, the central angle betweentwo consecutive depressions should be between 20° and 30°, with apreferred value of 25°. The central angle for the length of thedepression should be between 15° and 25°, in particular 20°.

During the introduction of the adhesive agent, the support body, whichas mentioned above preferably possesses a ring-shaped orhollow-cylindrical geometry with edges extending in parallel to eachother, is fixed in position, such as clamped, in order to subsequentlyfill the individual depressions, i.e. pockets, with an adhesive agent.Since preferably pocket-shaped depressions originate from each of theedges, a suggestion to be emphasized intends that the depressionsoriginating from one edge have the same distance from a reference markof the support body as the depressions originating from the other edgeafter a rotation of the support body by 180° about its transverse axis.

This ensures that the pockets are always in the same position duringfilling, i.e. independent of whether the one or the other edge of thesupport body faces the adhesive agent filling device.

To ensure that the adhesive agent does not flow through and exit the gapbetween the blank and the support body before curing, a characteristicfeature that also is to be emphasized intends that from the innersurface, i.e. from the wall of the support body, project baffles thatinhibit the free flow of the adhesive agent. The baffles hereby so tospeak provide the option of an adhesive reservoir. In this respect, itis in particular intended that the structure in a supplementary oralternative manner is formed by at least one elevation such as a ridgeand/or depression originating from the wall, whereby preferably theelevation and/or depression extending at some distance from the edge isprovided in addition to the at least one preferably pocket-shapeddepression.

In particular it may be intended in this connection that in the centralarea of the inner circumferential surface extends a preferablycircumferential ridge or depression such as a groove, which inparticular extends in parallel to the edges.

To arrange the blank in the support body with an equidistant distance tothe circumferential surface it may further be intended that one orseveral projections originate from the inner circumferential surface,such as for example ridges that at least in sections extend with aheight higher than that of the inner circumferential surface and serveas support for the blank.

Materials that are preferred for the manufacture of the ring-shaped orhollow-cylindrical support body are fiber reinforced materials such asglass fiber reinforced plastics such as thermoplastics, whereby thethermal expansion coefficient WAK_(H) of the material of the supportbody should be matched to the thermal expansion coefficient WAK_(R) ofthe blank, in particular so that the WAKs differ no more than 20%,preferably not more than 10%.

The content of fiber, such as glass fiber, of the plastic such asthermoplastic should be between 30% by volume and 70% by volume, inparticular approximately 50% by volume.

In particular the support body 10 consists of polyarylamide with a glassfiber content of between 30% by volume and 70% by volume, in particular50% by volume.

Further details, advantages, and distinguishing features of theinvention are not only found in the claims, the characteristic featuresdescribed therein—individually and/or in combination—, but also in thefollowing description of a preferred embodiment example.

The figures show a support body 10 with a wall 11 of ring-shaped orhollow-cylindrical geometry that surrounds a receiving opening 13 toaccommodate a blank 12, which in particular consists of ceramic andpossesses a disk-shaped or hollow-cylindrical geometry, as is shown inFIG. 4. In this, the support body 10 surrounds the blank 12circumferentially, i.e. the inner geometry of the support body 10 shouldmatch the circumferential geometry of the blank 12, if necessary with arequired undersize of the blank 12.

The support body 10 is required to be able to process the blank 12,which for example may be a zirconium oxide blank, in a processingmachine such as a milling machine, to produce for example a dentalrestoration.

The blank 12 is fixed in position within the support body 10 by means ofan adhesive agent, in particular a UV curing adhesive. For this it isnecessary to introduce the UV curing adhesive into the gap between theblank 12 and the support body 10. Capillary action draws the adhesiveinto the gap between the blank 12 and the support body 10. However,introducing the adhesive into the gap is not problem-free.

In order to facilitate this and still to maintain the stability of thesupport body 10, i.e. without weakening the thickness of the wall 11 ofthe support body 10, but at the same time to be able to introducesufficient amounts of adhesive easily even in the case of narrowdistances between the inner circumferential surface 14 of the wall11—hereinafter simply referred to as inner surface—and the outer surface16 of the blank, the invention's teaching provides for a pattern ofpocket-shaped depressions in the inner circumferential surface 14, i.e.the wall 11 of the support body 10, which as an example are marked withthe reference labels 18, 20, 22, 24. In this, the pocket-shapeddepressions 18, 20, 22, 24, which hereinafter will be referred to aspockets, originate directly at the respective edge, i.e. from the upperedge 26 and the lower edge 28 in the drawing. In this respect thedrawing is self-explanatory. The pockets 18, 20, 22, 24 possess firstsurfaces 30, 32, 34, 36 that extend along the inner circumferentialsurface 16 and obliquely thereto, which results in a ramp-shapedgeometry. The angle between the respective first surfaces 30, 32, 34, 36and the inner circumferential surface 14 may be between 20° and 30°, andin particular may be 25°. The first surfaces 30, 32, 34, 36 are borderedby lateral surfaces—two of which have been marked with the referencelabels 38, 40 as an example—, which with the first surfaces 30, 32, 34,36 enclose an obtuse angle, as is illustrated in the top view of FIG. 2.Both in a top view and in a sectional view the respective first surface30, 32, 34, 36 and the lateral surfaces 38, 40 generate a trapezoidalgeometry, as is made evident in the top view of FIG. 2, without thisconstituting any limitation on the invention's teaching.

However, the support body 10 not only exhibits a trapezoid geometry in atop sectional view but also in a front view, i.e. in a view from theinterior of the support body 10 in the direction towards the innercircumferential surface 14, as is shown in FIG. 3. In other words: Thefirst surface 30, 32, 34, 36 possesses a trapezoidal shape.

The perspective representation of FIG. 1 further illustrates that thepockets 18, 20 originating from the upper edge 26 are offset in such away from the pockets 22, 24 originating from the lower edge 28 that thepockets originating form one edge are situated in the spaces between thepockets originating from the other edge and vice versa. In this, thepockets 18, 20, 22, 24 are arranged in a way so that after a rotation ofthe arrangement 10, the pockets that have moved to the top have assumedthe exact same positions relative to a reference mark, which in theembodiment example is embodied in form of a longitudinal groove 42, sothat filling of adhesive material can always take place at the samepositions and thus can easily be automated.

In other words: If the support body 10 is rotated by the reference markamount, then positions of the pockets 18, 20 which in the drawing arenow at the top, will have been occupied by pockets that in the graphicrepresentation originate from the lower edge 28.

The figures further illustrate that longitudinal ridges originate fromthe inner surface 14, in particular from the lower pockets 22, 24 in thepresent embodiment example. A corresponding ridge is labelled with thereference label 44 as an example (FIG. 5). This ridge 44, which extendsin parallel to the longitudinal axis of the support body 10, protrudesinto the interior of the support body 10 to such an extent that a blank12 accommodated in the support body 10 is positioned relative to theinner surface 14 in a way so that one obtains a gap width between theblank 12 and the support body 10 that is constant along the entirecircumference.

If the length of each pocket 18, 20, 22, 24 along the circumferentialdirection is A2, then the distance A1 between consecutive pockets 18,20, 22, 24 should be greater than that. This distance is labelled A1 inFIG. 2. In particular, the distance A1 between successive depressions18, 20, 22, 24, i.e. in the area of the lowest wall thickness, withrespect to the length A2 of the respective depression along thecircumferential direction should obey A2≤A1≤2A2.

With respect to the wall thickness of the wall 11 at the origin of thepockets 18, 20, 22, 24, i.e. at the edge 26, 28, and with respect to thewall thickness of the wall 11 outside of the pockets 18, 20, 22, 24 itshould be noted that they should obey proportions such as 8*D1≥D2≥2*D1,whereby D1 is the wall thickness in the area of the origin of thepockets 18, 20, 22, 24 and D2 represents the wall thickness outside ofthe pockets 18, 20, 22, 24.

To mention specific figures; the wall thickness D2 can for example be1.5 mm to 5.0 mm, in particular 2.5 mm and the wall thickness in thepocket 18, 20, 22, 24 entrance area can be for example 0.5 mm to 0.9 mm,in particular 0.7 mm.

The height of the holding bracket 10 may for example be between 5 mm and30 mm, in particular in dependence of the height of the blank to beaccommodated, which preferably possesses an extent of its height that isgreater than that of the support body 10, i.e. its circular outersurfaces 44, 46 project beyond the edges 26, 28.

The inner diameter of the holding bracket 10 may for example be 94 mm to100 m, to provide some exemplary figures.

Between the edges 26, 28, which extend parallel relative to each other,in the central area of the support body 10 and in particular originatingfrom the inner surface 14, extends a preferably circumferential ridge 43(FIG. 1, 5), which prevents the adhesive agent flowing through the gapbetween the blank 12 and the support body 10 from dripping out on theopposite side. Rather, the corresponding ridge 43 in this respect actsas a baffle. Other geometries for the retention of the adhesive agentare of course also possible. The ridge 43 is forming a structure.

Feasible materials for the support body 10 are in particularly fiberreinforced such as glass fiber reinforced plastics such asthermoplastics, whereby the thermal expansion coefficient WAK_(H) of thematerial of the support body 10 should be matched to the thermalexpansion coefficient WAK_(R) of the blank 12; in particular the WAKsshould differ no more than 20%, preferably no more than 10%. The fibercontent, such as glass fiber content, of the plastic, such asthermoplastic, should be between 30% by volume and 70% by volume, inparticular approximately 50% by volume.

In particular, the support body 10 consists of polyarylamide with aglass fiber content of 30% by volume to 70% by volume, in particular 50%by volume.

Irrespective hereof, the figures are self-explanatory and illustrate thecharacteristic features of the support body 10 of the inventionunambiguously.

The invention claimed is:
 1. A support body for a blank comprising areceiving opening for the blank, the support body further comprising aninner surface bordered by an upper and a lower edge and when the blankis fixed in position within the support body, the blank is bonded to thesupport body by means of an adhesive agent, wherein the inner surfaceincludes a structure in form of a plurality of depressions that extendsto at least one of the upper and lower edges, at least one elevation, orboth to accommodate the adhesive agent; wherein the plurality ofdepressions are bordered by a first surface extending along the innersurface and between lateral surfaces extending perpendicularly to theinner surface; wherein an angle α is defined between the first surfaceof the plurality of depressions and the inner surface to be between20°≤α≤30°; wherein in a central area of the inner surface extends aridge, which extends in parallel to at least one of the upper and loweredges to prevent the adhesive agent flowing through a gap between blankand support body from dripping out on an opposite side; and wherein fromthe inner surface originate one or several projections such thatsections of the one or several projections extend above or below theridge to serve as support for the blank.
 2. The support body of claim 1,wherein the plurality of depressions include a plurality ofpocket-shaped depressions within a thickness of the wall of the supportbody that is bordered by the inner surface.
 3. The support body of claim1, wherein the plurality of depressions originate from a receiving-sidearea of both the upper and the rower edge, and which terminate at somedistance from the center of the inner surface.
 4. The support body ofclaim 1, wherein a distance from the first surface to a central axis ofthe support body decreases from one edge along the direction towards anopposite edge.
 5. The support body of claim 1, wherein the pluralitydepressions are uniformly distributed along the inner circumference ofthe support body.
 6. The support body of claim 1, wherein the pluralityof depressions originating from a first edge of the at least one edgewill exhibit the same distances to a reference mark of the support bodyas the plurality of depressions originating from a second edge of the atleast one edge after a rotation of the support body by 180° about itstransverse axis.
 7. The support body of claim 1, wherein the structureis formed by at least one elevation, at least one depression, or boththat extends at some distance to a first edge of the at least one edgeand originates from the inner surface of the wall.
 8. The support bodyof claim 7, wherein the at least one elevation, the at least onedepression, or both extending at some distance to the first edge isprovided in addition to a plurality of pocket-shaped depressions of theplurality of depressions.
 9. The support body of claim 1, wherein theinner surface at least partially surrounds the blank.
 10. The supportbody of claim 9, wherein the inner surface completely surrounds theblank.
 11. The support body of claim 1, wherein the plurality ofdepressions is formed within a thickness of a wall of the support bodythat is bordered by the inner surface.
 12. The support body of claim 1,wherein in an area of at least one of the plurality of depressions, thewall of the support body in an edge area possesses a thickness D1 andthe wall outside of at least one of the plurality of depressionspossesses a thickness D2, whereby 8*D1≥D2≥2*D1.
 13. The support body ofclaim 1, wherein a distance A1 between successive depressions and alength A2 of one of the successive depressions along the direction obeysA2≤A1≤2*A2.
 14. The support body of claim 1, wherein the support bodyincludes a material that includes plastic, wherein the thermal expansioncoefficient WAK_(H) of the material is matched to the thermal expansioncoefficient WAK_(R) of the blank, and wherein the thermal expansioncoefficients differ no more than 20%.
 15. The support body of claim 1,wherein the support body includes a material that includes plastic,wherein the thermal expansion coefficient WAK_(H) of the material ismatched to the thermal expansion coefficient WAK_(R) of the blank, andin particular wherein the thermal expansion coefficients differ no morethan 10%.
 16. The support body of claim 15, wherein the plastic is afiber reinforced plastic.
 17. The support body of claim 16, wherein thefiber reinforced plastic is a glass fiber reinforced plastic.
 18. Thesupport body of claim 17, wherein the glass fiber reinforced plastic isa thermoplastic.
 19. The support body of claim 17, wherein the fibercontent of the support body amounts to between 30% by volume and 70% byvolume.
 20. The support body of claim 1, wherein the support bodyincludes a hollow cylindrical geometry and at least partiallycircumferentially surrounds the blank.